Air freshening devices are a popular means of eliminating common odors from a home. These odors frequently result from bathrooms, pets and cooking, but can originate from a number of sources. The air freshening device adsorbs disagreeable scents, such as litter box smells or frying onions, and/or replaces them with pleasant natural scents like flowers or ocean breezes. Many devices that attack this problem, but function in different ways, are known in the art.
One method of air freshening is through use of a plug-in scenting device, as taught in U.S. Pat. No. 5,136,684. This device plugs into an electrical outlet and uses energy to heat a fragrant gel to scent the area around the device. However, there are disadvantages to this device. It cannot be used where no electricity is available. It consumes energy to distribute the scent. Further, it cannot scent a large area.
In attempts to scent larger areas, fragrance has been incorporated into air filters, as taught in U.S. Pat. No. 5,817,168. A grid of scent-impregnated strands is positioned on the incoming or front side of an air filter. Scent is transferred to the air as it moves through the filter. A similar device is taught in U.S. Pat. No. 4,604,114, where rods containing scent delivering means are inserted into and run from edge to edge of an air filter. Yet another fragrance device attached to an air filter is taught in U.S. Pat. No. 5,861,128. One problem with these filters is that the scent emitted by these filters cannot be adjusted. Additionally, the scented media are incorporated into or permanently attached to the filters themselves, and thus cannot be reused or transferred from one filter to another.